Authors:

Abby Goldman(Mount Holyoke College)

Tianyu Yang(University of Massachusetts, Amherst)

Mark Tuominen(University of Massachusetts, Amherst)

Kathy Aidala(Mount Holyoke College)

Ferromagnetic nanorings form unique magnetic states that hold
tremendous
promise for maximizing storage densities. One such state is the
vortex
state, in which the magnetic field is completely enclosed within
the ring,
though it is challenging to control the chirality. We study a
straightforward method to control the clockwise or counterclockwise
chirality using an azimuthal field, as if from a current carrying
wire
passing through the center of the ring. Our simulations predict the
formation of 360 $^{\circ}$ domain walls during switching of 5 nm
thick rings in a
variety of geometries. The number and location of the domain
walls depends
on the ring geometry. We explore the reason 360 $^{\circ}$ domain
walls form for
different widths, asymmetries, and sizes. Experimental
implementation is
underway to confirm computational predictions. The micromagnetic
simulations
are performed using OOMMF, Object Oriented Micro Magnetic
Framework, a
public domain program distributed by NIST to study the evolution
of magnetic
states with the application of a circular magnetic field.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.J36.5